1. Field of the Invention
The present invention relates to an embroidery sewing machine having an embroidering frame holding a work to be stitched and a mechanism for moving the embroidering frame relative to a vertically reciprocating needle, and more particularly relates to an embroidery sewing machine which is responsive to the turning off operation of a power source switch to withdraw the embroidering frame from a position where the same is partly extended out from the base of sewing machine to a predetermined position where the embroidering frame is substantially located on the base of sewing machine.
2. Prior Art
Generally an embroidery sewing machine is operated to move an embroidering frame holding a work to be stitched in X-Y direction relative to a vertically reciprocating needle, thereby to form stitches on the work.
The embroidering frame is moved in a limited area which is determined in connection with an area in which a frame moving mechanism of the sewing machine may move. In case of the embroidery sewing machine, the frame moving mechanism is generally housed in a base of the sewing machine of a limited space. The embroidering frame is accordingly limited to move relative to the vertically reciprocating needle, additionally with existence of a standard portion of the sewing machine occupying a considerable part of the sewing machine body.
However, recently a frame moving mechanism has been proposed by the same applicant of this patent application, the frame moving mechanism including a moving assembly having another moving assembly additionally provided thereon to be relatively moved thereto formed as a multi-stepped moving assembly. According to the frame moving mechanism, the embroidering frame may be moved in a larger area than the area limited by the space of the base and by the standard portion of the sewing machine.
But apart from this advantage, in case the power source is turned off while the embroidering frame is partly extended out from the base of sewing machine and remains to be returned to a predetermined rest or inoperative position, or in case the sewing machine is stopped during stitching operation due to power failure or disconnection of electric cord from the power source, the sewing machine may happen to remain as occupying a large area or space with the embroidering frame being considerably extended out from the sewing machine. Further, in case the thread is changed from one color to another during embroidering operation while the embroidering frame is extended out from the sewing machine, the embroidering frame will become an obstacle to the thread changing operation. Particularly the multi-stepped moving assembly is mechanically fragile to impact or load, and further it is rather difficult to provide a mechanism that is manually operated to withdraw the embroidering frame to the rest or inoperative position.
The invention has been provided to eliminate the defects and disadvantages of the prior art. It is, therefore, a primary object of the invention to provide an embroidery sewing machine which is prevented from being left with the embroidering frame being partly extended out from the base of sewing machine while the sewing machine remains unused.
It is another object of the invention to provide an embroidery sewing machine which is responsive to the turning off operation of a power switch to withdraw the embroidering frame from a position where the same is partly extended out from the base of sewing machine to a predetermined position where the same is substantially located on the base of sewing machine.
It is another object of the invention to provide a memory for memorizing a stitching position of the embroidering frame so that the embroidering frame may be automatically returned to the stitching position from the withdrawn position.
It is another object of the invention to provide a detector for detecting turning off operation of a power switch and a device operated in association with the detector to maintain supply of power until the embroidering frame is withdrawn to the predetermined position.
It is another object of the invention to provide a detector for detecting a predetermined elapse of time after the power source switch is turned off and a device operated in association with the detector to withdraw the embroidering frame to the predetermined position and simultaneously intercepting the power source.
It is another object of the invention to provide a loose stitch preventing program memory so that the stitches may be formed to prevent the preceedingly formed stitches from being loose before the embroidering frame is withdrawn to the predetermined position.
It is another object of the invention to withdraw the embroidering frame a shortest allowable distance towards the base of sewing machine so that the embroidering frame may be quickly returned to the stitching position.
It is still another object of the invention to initialize an embroidering frame carrying member prior to starting the embroidery stitching operation or the purpose of avoiding interference of the embroidering frame with another member of the sewing machine during withdrawing movement of the embroidering frame to the predetermined position.
For attaining the objects, the embroidery sewing machine of the invention comprises a stitch forming means including a vertically reciprocating needle, a means for holding a work to be stitched, a moving means for moving the work holding means relative to the vertically reciprocating needle, wherein in case a power source switch is turned off, the sewing operation is interrupted for a predetermined period of time, or an instruction is given to withdraw the moving means to a predetermined positron (or a position where the moving position is housed), the moving means is automatically operated to withdraw to the predetermined position. Thus, the sewing machine may be prevented from being left unused while the work holding means remains as is extended out from the sewing machine.
The power off condition is detected by a detector and subsequently power is maintained as supplied by a power supply maintaining means such that the moving means may be operated by the maintained power to withdraw to the predetermined position.
According to the invention, in case the power source is intercepted, power is maintained to withdraw the moving means. Therefore, the sewing operation will not be interrupted for a long time without withdrawal of the moving means to the predetermined position. The means for maintaining the power supply may include various means. This means may, however, be something responsive to a switch-off signal to immediately postpone the power interception for a predetermined period of time. In this connection, a battery may be provided as a power source to be automatically switched over thereto at the time of power interception. This may cope with power failure or incidental disconnection of power cord.
Interruption of sewing operation for a predetermined period of time may be detected by a detector for detecting the stopped condition of the stitch forming means and the work holding means, and discriminated by a means for deciding if the stopped condition has continued for a predetermined period of time and for withdrawing the moving means to the predetermined position at the end of the predetermined period of time. Therefore, since the moving means moving the work holding means is withdrawn to the predetermined position in case the sewing machine has been stopped for a predetermined period of time, the sewing machine may be prevented from being left unused for a long time while the work holding means remains as is extended out from the sewing machine. Preferably, the predetermined period of time may be optionally set by the user by operating a means provided for setting the period of time.
The instruction for withdrawing the moving means may be given by the user who operates an operating means provided to be accessed by the user and the instruction may be carried out by a means responsive to operation of the operating means to withdraw the moving means to the predetermined position. Thus, the withdrawing means will operate in response to operation of the operating means to withdraw the moving means. Therefore, the sewing machine may be prevented from being left unused while the work holding means remains as is extended out from the sewing machine in case the sewing operation is interrupted. The withdrawing means may be provided as indicated, for example, at a touch panel of a display.
The moving means may be of a multi-stepped extendible mechanism composed of at least two moving assemblies, wherein one moving assembly has another moving assembly mounted thereon to be movable relative thereto. On the other hand, the withdrawing means is preferably formed to withdraw more than a half of the total length of the moving assemblies. In case at least more than a half of the total length of the moving assemblies is withdrawn, the moving assemblies may be prevented from damage which may otherwise be caused at the time of impact given thereto.
Further, a means may be provided to be operated by the user for optionally setting the predetermined position to which the moving means is withdrawn, and further a means may be provided to be operated in accordance with information including a weight of the moving means to automatically decide the predetermined position.
Preferably a means is provided for detecting a position of the work holding means so that the position of the work holding means prior to withdrawal to the predetermined position may be memorized for the purpose of automatically returning the work holding means to the memorized position.
The withdrawing direction may be either or one of the X and Y directions. However, normally the width direction (Y direction) is sufficient.
It is further preferable that the stitches may be formed for preventing loosening of the preceedingly formed stitches before the work holding means is withdrawn to the predetermined position so that the embroidery stitching operation may be started again smoothly.
Further, a means may be provided for rendering the sewing machine into an economy mode to save power immediately after the work holding means or the moving means has been withdrawn to the predetermined position.
Further, during withdrawing movement of the moving means to the predetermined position, it may happen that the work holding means (embroidering frame) will contact the other constituent member or members of the sewing machine. This problem must be taken into consideration especially in case the work holding means is capable of movement in a larger area.
In order to solve the problem, it is preferable to provide a means for detecting prior to withdrawal of the moving means if the work holding means is mounted or not on the moving means so that the moving means may be withdrawn to the predetermined position only when the work holding means is not mounted to the moving means. The permission that the moving means may be withdrawn to the predetermined position only when the work holding means is not mounted to the moving means may be applied additionally to the cases wherein the power source switch is turned on or off, wherein the moving means is withdrawn when the sewing machine is switched over from embroidery stitching to ordinary stitching, or wherein the moving means is subjected to initializing operation to move to the original stitching point at the time of starting the embroidery stitching operation.
In case presence of the work holding means is detected, the initializing operation may be carried out immediately or in response to an initializing instruction to be given after the work holding means is removed from the moving means. It is preferable to provide a means for giving a notice to the user in case presence of the work holding means is detected. Further, in case the initializing operation is carried out in response to the initializing instruction, it is preferable to provide a means for giving a notice to the user to give the initializing instruction. The noticing means nay be a display which is normally provided on the sewing machine.